1. Field of the Invention
The present invention relates to a four-directional control switch used for controlling various compact electronic apparatuses.
2. Background Art
FIG. 12 shows a sectional front view of a conventional four-directional control switch, and FIG. 13 shows a plan view of a switch case accommodating movable contacts. Central-fixed contact 3 (hereinafter referred to as xe2x80x9ccontact 3xe2x80x9d) is placed on a center of an inner bottom of quadrangular switch case 1 (hereinafter referred to as xe2x80x9ccase 1xe2x80x9d) whose top is open. Contact 3 is formed of common contact 2 and central contact 3A for a central switch. As shown in FIG. 13, four individual-fixed contacts 4A-4D (hereinafter referred to as xe2x80x9ccontacts 4A-4Dxe2x80x9d) for peripheral switches are placed at four corners of the inner bottom of case 1, and respective leading terminals are protruded from an outer periphery of case 1. Besides, in FIG. 13, movable contact spring 5 (hereinafter referred to as xe2x80x9cspring 5xe2x80x9d) made of an elastic thin metal plate is formed by coupling dome-shaped central movable contact 6 (hereinafter referred to as xe2x80x9ccontact 6xe2x80x9d) with individual-movable contacts 7A-7D (hereinafter referred to as xe2x80x9ccontacts 7A-7Dxe2x80x9d) via coupling section 5A. Contact 6 corresponds to contact 3, and contacts 7A-7D respectively correspond to contacts 4A-4D. Spring 5 is accommodated in case 1 in a manner that contact 6 and contacts 7A-7D respectively face toward contact 3 and contacts 4A-4D. Operating unit 8 and stick 9 are disposed on spring 5. Operating unit 8 is formed of cylindrical section 8A and skirt section 8B at its lower part. Stick 9 is held independently and movably in a vertical direction through central hole 8C of operating unit 8. Four hemispherical protrusions 10A-10D (hereinafter referred to as xe2x80x9cprotrusions 10A-10Dxe2x80x9d) of a bottom of skirt section 8B respectively come into contact with tops of contacts 7A-7D, where protrusions 10B and 10D are not shown in the drawings. Bottom section 9A of stick 9 comes into contact with a top of contact 6. Operating unit 8 is rockably held through central hole 11A of cover 11 covering the top of case 1.
For example, as shown by an arrow in a sectional front view of FIG. 14, the four-directional control switch is operated by tilting stick 9 in a direction of one of the four corners of case 1. Thus, operating unit 8 also rocks and tilts, so that protrusion 10A of the bottom of skirt section 8B, which has been tilted and moved downward, presses downward contact 7A corresponding to protrusion 10A. As a result, contact 7A is elastically inverted. Contact 7A comes into contact with contact 4A, thereby permitting conduction between certain leading terminals. When pressing-force against stick 9 in the tilted direction is removed, the four-directional control switch is returned to an original state shown in FIG. 12 by elastic restoring force of contact 7A. When stick 9 is tilted in the direction of another one of the four corners, the same operation is executed, thereby permitting conduction between certain leading terminals. Then, when pressing-force is removed, the four-directional control switch returns to the original state.
As shown by an arrow in a sectional front view of FIG. 15, when stick 9 is pressed in a vertical downward direction, only stick 9 moves straight and downward. Thus, bottom section 9A presses contact 6 downward and elastically inverts contact 6. Then, contact 6 comes into contact with central contact 3A of contact 3, thereby permitting conduction between certain leading terminals. When pressing-force against stick 9 in the downward direction is removed, the four-directional control switch is returned to the original state shown in FIG. 12 by elastic restoring force of contact 6.
The conventional four-directional control switch discussed above is disclosed in Japanese Patent Unexamined Publication No. 2001-351478.
The conventional four-directional control switch has individual-switches at the four corners of quadrangular case 1, so that case 1 can be downsized. However, in an electronic apparatus using the conventional switch, stick 9 is generally tilted in a direction of front, rear, right or left when operated. Therefore, when the conventional switch is mounted on the electronic apparatus, case 1 has to be mounted on the electronic apparatus at a 45xc2x0 angle with respect to a side of a casing of the electronic apparatus. In a word, case 1 needs to be mounted at an angled. Thus, an area corresponding to a quadrangle whose one side corresponds to a diagonal line of case 1 is needed for a space in the casing of the electronic apparatus. As a result, the conventional switch cannot effectively use a space in the casing of the electronic apparatus and is disadvantageous for downsizing of the electronic apparatus.
A four-directional control switch presses one of four elastic arms, whose flange section has a stiffness characteristic, by tilting a controlling unit formed of a stick and a flange section. The pressed elastic arm operates one of individual-switches disposed at four corners of a switch case. Each elastic arm extends from each side of the switch case to at least a middle point of a side, which is adjacent and parallel to the arm.